Question

Помогите пожалуйста с 1 номером )

Answer 1

$1) frac{y-4}{3y-3}+ frac{1}{y-1}= frac{y-4}{3(y-1)}+ frac{1}{y-1}= frac{y-4+3}{3(y-1)}= frac{(y-1)}{3(y-1)}= frac{1}{3}$

$2) frac{1}{3}: frac{y+1}{3}= frac{1*3}{3*(y+1)}= frac{1}{(y+1)}$

$3) frac{1}{y+1}+ frac{2}{ y^{2}-1}= frac{1}{y+1}+ frac{2}{(y-1)(y+1)}= frac{y-1+2}{(y-1)(y+1)}= frac{(y+1)}{(y-1)(y+1)}= frac{1}{y-1}$